/Engine/Source/Runtime/Datasmith/CADKernel/Public/CADKernel/Math/SlopeUtils.h
Swap a slope i.e Slope + PiSlope i.e. angle + Pi
a slope between [0, 8]
namespace UE { namespace CADKernel { double UE::CADKernel::SwapSlopeOrientation ( double Slope ) } }